Fotjeth to d estaing s



(No Model.) 2 Sheets-Sheet 1.

M. D. BRETT.

SMELTING oRl-"Js.

No. 320,908. atnted June 30, 1885 oumo n hnr. wahingwm n1;

(No Model.) 2 Sheets-Sheet 2. M. D. BRETT.

SMELTING ORES. No. 320,908. Patented June 30, 188 5.

UNITED STATES PATENT OFFICE.

MATHEW DAUSON BRETT, OF DENVER, COLORADO, ASSIGNOR OF ONE- FOURTH TODESTAING S. COVERT, OF SAME PLACE.

SMELTI'NG ORES.

SPECIFICATION forming part; of Letters Patent No. 320,908, dated June30, 1885,

(No model.)

To all whmn it may concern:

Be it known that I, MATHEW D. BRETT, a citizen of the United States,residing at Denver, Arapahoe county, State of Colorado, have inventedcertain new and useful Improvements in Smelting Ores,of which thefollowing is a specification.

My invention relates to smelting ores, and has for its object to improveand simplify the manner and means for smelting, so that all manner ofores carrying lead, gold, or silver, or a combination of any and all ofthem, may be economically treated; and to this end my invention consistsin the methods and means hereinafter pointed out for producing theseeffects.

I11 the accompanying drawings, forming part of this specification,Figure 1 is a plan view of the furnace, partlyin section, and Fig. 2 isa longitudinal section on the lines at m, Fig. 1.

A sump or crucible, A, is formed in the shape of a basin or dish, and ismade of common red or fire brick, and is surrounded by the proper amountof masonry of the usual red-brick work. The interior of the sump may belined with any usual or suitable material that will not contract orexpand under the heat or allow the molten metal to penetrate or escapefrom it. At the side of the sump, and connected to its bottom by asuitable passage, is arranged a lead-well, thetop of which is of such aheight as to allow the excess of lead to overflow and maintain themolte11 lead in the sump at a proper level. This level is preferablyabout two inches from the top of the sump, and this space is occupied bya molten matte or blanket of fluxes and reagents, serving as a coveringto protect the bat-h of lead from scorification; also as a bed uponwhich to effect the final separation of the metallic constituents ofores from the gangue, matrix, or core contained therein. The sump iscovered with an arch having suitable openings to connect with thefire-boxes and expansion-chamber. A slag tap-hole, B, and a mattetap-hole, C, are formed at the base of the arch, and a peep-hole, O, is10- rated in a suitable position to allow the workman to watch theoperations. Outside of the walls of the sump are located severalfireboxes, Q, two being shown in the drawings. These fire-boxes consistof proper masonrywork, forming the ash-pit T, the fire-place I havingthe grate-bars R supported in the walls, an arched covering, Q, made torest upon the walls, and provided with a suitable door, U,

preferably having a slash bar-hole, V, for stirring the fire, an openingfor the superheated steam and oil pipes \V, and in the top of the archan opening supplied with. any of the ordinary feeding devices forfeeding the fuel directly into the middle of fire-place. The top of thearch is contracted at the end, as seen at a, where it enters thesumparch, for the purpose of concentrating in a blow-pipe manner theheat and flames, as more particularly set forth hereinafter. Suitabledoors for regulating the draft and disposing of the ashes may bearranged in any desired manner. On the opposite side of the sump arearranged the oreconveyer, desulphurizer, expansion and con- (lensingchambers, and other appliances for completing the smelting process.

The ore-conveyer F consists of a long tube or cylinder perforated atintervals throughout its length, as at H H, provided with a suitablehopper, I, and ascrew-shaft, G, adapted to be rotated by suitable means,as pulley G. The inner end of the tube or pipe extends within thesump-arch and over the matte and lead-well. Around the conveyer isformed an expansion or dust chamber, K, through which the products ofcombustion are drawn, and from which they pass into thecondensingchamber L through the inlet-holes D, where they are subjectedto a spray or stream of water, whence the fumes and heat pass throughthe outlet-hole M, being drawn therethrough by suitable exhaustingapparatus, as a fan. Any precious metal that has been carried by thefumes into the condensing-chamber will be deposited by the spray orstream of water into the condensing-chamber, and, passing through thehole N, will be carried into the settling-pans, where it is gathered inamanner well understood, and is preferably placed in a bag, when it ispassed directly into the center of the combustion chamber by beingdropped through the hole P in the top of the sump-arch.

The operation of my furnace is as follows:

The lead-well being filled and the mattebeing supported upon the lead,and the fires in the fire-boxes being kindled,the ore, and fluxes, whennecessary, is fed into the hopper I of the conveyer pipe or tube, andthe screw-conveyer being turned by proper means, the ore is slowly fedtoward the interior of the sump. The products of combustion at the sametime, passing through the smoke-chamber around the conveyer, heat thesame and desulphurize the ore in the conveyer, the fumes escaplng by thefume-holes H H, and pass through the dust and condensing chambers K L,being drawn therethrough by the exhausting apparatus. As the ore isslowly fed through the conveyer, the desulphurizing process iscompleted, and it passes out of the conveyer in a liquid or semiliquidform, when it meets the flames and heat from the fire-boxes, the boxesbeing arranged and constructed, as before set forth, so as to direct theflames at this point, and the smelting takes place in thecombustion-chamber of the sump-arch, the molten matte or blanket actingas a separating agent. The ore in its molten or semi-molten state fallsupon this blanket, and in passing over it to the slag tapholeprecipitates its metals into the blanket, the precious metals, owing totheir greater specific gravity, going through into the lead-well and tothe dipping-cup, while the refuse or slag, being lighter than the matte,passes over the top of it out of the slag-holes. The vaporizableproducts of combustion are drawn by the exhaust apparatus through thesmoke-space,heating the ore-conveyer and desulphurizing the ore; thencethey pass to the dust or expansion chamber, thence through the openingsD into the condensingchamber L, where they come in contact with a sprayor stream of water and pass through the outlet-hole M into the chimney.The precious metals contained therein, being deposited into the bottomof the condensingchamber, pass through the water discharge hole N intosuitable separating-pans or settling-tanks, as before stated.

From the above the advantages of my improved furnace are apparent. I usebut one hearth or sump, which acts as.a crucible for holding thepermanent bath of molten lead, which latter may be introduced into thesump prior to feeding the ores, or may result from the reduction of themetallic lead from the stock operated. This bath acts a medium forcollecting and holding in alloy as base bullion any gold or silvercontained in the stock treated, and which is reduced to a metallic statedirectly in contact with the matte and bath in the combustion-chamber ofthe sump. As the volume of the bath increases by the reduction of leadin the stock treated, it is dipped from the lead-well E or allowed tooverflow into molds, and is ready to ship as base bullion; or it may berun over a series of refining-plates and the precious metals separatedfrom the base or lead bullion.

A very important feature of my invention is the molten matte or blanketcontained in the sump above'the lead. Thisblanket or matte is formedautomatically from the various reagents .fed with or found in the ores,and when once formed is permanent, its volume being sustained from theores fed to the furnace, and any excess or surplus flowing off by thematte tap-hole, which is continuously open.

As before stated, the lead in the sump is automatically maintained atthe proper level, and the blanket or matte is also automaticallymaintained, and thereby the lead is always properly covered by thematte, preventing scorification, and the slag freely flows off at theopen slag-hole.

By arranging the furnaces as above de scribed the heat and flames fromthe fuel used, which may be of any desired character, are carried fromthe fire-boxes through the funnel -shaped throats into the combustionchamber, where they meet, being concentrated upon the smeltingpoint, andcrossing each other in the sump they produce a sort of rotary flame,which is practically confined within the sump-arch above the blanket,and I am thereby enabled to utilize the greatest amount of heat and atthe most effectual point.

Another feature of my invention consists in using an exhaust or suctionblower instead of a blast-blower, and by this means, while Iain enabledto keep up the requisite amount of draft for the furnaces, the blanketor matte is not seriously disturbed or broken, as when the blast isused, and scorifieation and loss of the lead is prevented. Moreover, onaccount of the arrangement of the furnaces and sumparch as aboveindicated, I am enabled to draw the waste products of combustion andtheheat through the expansion-chamber around the ore-conveyer more inthe form of heated gases, as very little, if any, flame escapes from thesump-arch. This I find is very advantageous in reducing ordesulphurizing them in the conveyer. \Vhere fluxes are necessary I mixthem with the ores in the conveyer, and thereby avoid the necessity offeeding them separately to the reducing-point. The hole P in the top ofthe sump-arch enables me to feed rich stock-such as the tellurides,chlorides, Ste-without loss directly into the lead bath.

While I do not desire to limit myself to the precise details andconstruction set forth, as they may be varied without departing from thespirit of my invention, I have found the above-described arrangementforms a practical smelter of great capacity and applicable to theeconomical and complete reduction of all ores carrying precious metals,and producing the same in the form of base or lead bullion.

I am aware ore has been fed through a cylinder, where it was roasted incontact with hot air to charge it with oxygen, and then fed into anothercylinder and roasted in direct contact with a flame, the sulphur beinglargely consumed and fluxes being added therein, and

ICC

then fed to the reducing-chamber, where the metals are precipitated intheir order of gravitation, and I make no claim thereto.

Having thus described my invention, what I claim is 1. The process ofsmelting ores, substantially as herein set forth, which consists ingradually feeding the ores through a conveyer, subj ecting them thereinto a temperature sufficient to desulphurize and reduce them to asemi-liquid state by the action of hot air, and concentrating the flamesand heat from several sources directly upon the semi-liquid mass.

2. The combination,with a sump having an arched top or dome, of a seriesof fire-boxes, constructed and arranged substantially as described, andinclined concentrating-passages leading from the boxes to the interiorof the sump, whereby the flames may be concentrated and confined in thesump, as and for the purposes described.

3. The combinatiomwith a sump, of an orcconveyer consisting of a tubehaving a suitable hopper and a screw-conveying rod and a series ofperforations in the tube, the whole being arranged in the exhaustsmoke-chamber leading from the sump, whereby the ores are desulphurizedand delivered directly at the smelting-point in a liquid or semi-liquidstate, substantially as described.

4. The combinatiomwith a sump having an arched top or dome containing alead bath and metallic matte, of a series of fire-boxes located at oneside of the sump, having inclined passages adapted to concentrate theflames and heat at the mouth of the conveyer, and a conveyer adapted todeliver the ore into the concentrated flames and heat, substantially asdescribed.

5. The combination, with an arched sump containing a lead bath and ametallic matte,

and provided with means for maintaining the same at a constant level, ofa series of fireboxes at one side of the sump, arranged to concentratethe heat and flames, an exhaust smoke-chamber at another side, and aconveyer located in said chamber, the arrangement being such that theflames and heat pass into the sump, are concentrated at thesmelting-point without scorifying the lead bath, and are drawn throughthe exhaust-chamber, heating the ore in the conveyer, substantially asdescribed.

6. The combination, with a sump and .fireboxes connected therewith,arranged to concentrate the flames and heat in the sump, of a smoke ordust chamber containing an oreconveyer, a condensing chamber connectedtherewith, an exhausting apparatus connected with thecondensing-chamber, whereby the flames and heat are drawn into the sumpand concentrated, and the products of combustion are drawn through thechambers, and means for supplying water to the condensingcham ber, asand for the purpose set forth.

7. The combination,with the sump contain ing a lead bath and a metallicblanket, of fire-boxes connected to said sump and a sumparch having anopening at the top and an oreconveyer located in thesmoke-chamber,whereby the ordinary ores may be conveyed to the sump in asemi-liquid state, and the rich ores may be dropped directly into thesump at the smelting-point, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

MATHEWV DAUSON BRETT.

Witnesses:

W'ILLIAM M. BROOKE, MEREDITH B. OAMPLIN.

